Slit Horizontal Hinges
In U.S. Pat. No. 7,260,860; Chambers et al. described a mattress assembly having a head end, a foot end, a right side, and a left side. The mattress has a horizontal slit hinge positioned from the right side to the left side of a foam mattress. That horizontal slit hinge assists the mattress assembly alter its position in a gatch bed. A gatch bed is a bed with divided sections for independent elevation (up and down) of a patient's head and knees.
That understanding of Chambers et al.'s hinge is confirmed in the following extract from the '860 patent: “The foam layers . . . of the core portion . . . include a laterally extending slit . . . defining a hinge to assist in bending of the mattress assembly . . . during articulation of the support deck . . . . Similarly, each width adjustment bladder . . . includes a slit . . . positioned [vertically] adjacent the slit . . . to define a hinge point. A tube . . . may be positioned within each bladder . . . at the hinge point to prevent the air flow path from being sealed when the mattress assembly . . . is bent.”
Accordingly horizontal slit hinges in foam mattresses that extend from the right side to the left side are known to those of ordinary skill in the art. Moreover, other than air nothing is positioned within the horizontal slit hinges.
Pivot Horizontal Hinges
In U.S. Pat. No. 7,246,388; DiLiberto, Jr. discloses an alternative to Chamber et al.'s horizontal slit foam mattress. Instead of using horizontal slits, DiLiberto, Jr. uses a “hinge assembly [comprising] a nylon tubing . . . , two washers . . . , a threaded T-nut . . . and a bolt . . . . That hinge assembly is positioned from the right side to the left side of the mattress. Like Chambers et al., DiLiberto, Jr.'s hinge assembly mattress is effective for a gatch bed. DiLiberto, Jr.'s hinge assembly is impractical for a rotating mattress because the tubing extends across the width of the mattress (right side to left side) and inhibits a mattress' rotating ability.
Rotating Mattress
Rotating a patient on an inflatable mattress is also well known to those of ordinary skill in the art. Rotating a patient is one method to avoid and/or decrease the formation of bed sores on immobile patients. A rotatable inflatable mattress and the method in which the mattress rotates the patient are disclosed in U.S. Pat. Nos. 5,794,289 and 5,926,883 which are commonly assigned and are hereby incorporated by reference.
In those patents, Gaymar Industries, Inc. illustrated FIGS. 1 and 2. In FIGS. 1 and 2, there is illustrated generally at 170 a mattress containing an inflatable cushion 180 which is tiltable to one side, as illustrated in FIGS. 3 and 4, for the purpose of rolling a patient, illustrated at 171, over, placing the patient in a better position for lifting from the mattress, or otherwise moving the patient as needed.
In a preferred embodiment, the mattress 170 includes a foam support member 172 on which rests a tilting assembly, illustrated generally at 174, which will be described hereinafter, the tilting assembly 174 disposed generally within and circumscribed about its periphery by a lower crib 176. The crib 176 in turn supports an upper crib 178, in which is contained the cushion 180. The cushion 180 may be any suitable cushion material including inflatable air bladders having button welds, illustrated at 186, uniformly spaced thereover to prevent ballooning thereof when pressurized.
The tilting assembly 174 comprises two sets of bladders, each set of bladders includes an upper and a lower inflatable bladder 182 and 184 respectively the width of each of which being slightly less than half of the width of cushion 180. The bladders 182, 184 are further divided into right bladders 182a, 184a and left bladders 182b, 184b. The foot end portions 188 of the lower bladders 184 are tapered over about one-third of the length thereof to allow relatively greater lifting capacity for the head end and central portions supporting the torso of a patient since the torso requires greater lifting capacity than the feet. The upper bladder 182 may be any suitable inflatable bladders and have button welds, illustrated at 186, uniformly spaced thereover to prevent ballooning thereof when pressurized. As seen in FIG. 1, each lower bladder 184 is absent button welds or the like so that it may desirably balloon when pressurized to lift the corresponding side of the cushion 180 as needed. Otherwise, bladders 182, 184 include inflation means, such as pumps and the like.
A fabric strip 190 can bridge across and is adhesively or otherwise suitably attached to the upper surface of crib 178 for lateral stability. The cribs 176 and 178 and support member 172 are adhesively or otherwise suitably attached, and the assembly including the tilting assembly 174 and cushion 180 are enclosed within a zippered mattress cover 175 as shown in FIG. 2.
FIG. 2 illustrates the mattress 170 with the cushion 180 in a level condition for the patient 171 to lie normally thereon. In this condition, the cushion 180 and upper bladder 182 are fully inflated while the lower bladder 184 is uninflated.
FIG. 3 illustrates tilting of the cushion 180 to about a 15 degree angle to one side by deflating the left side bladder 182b and by inflating the right side bladder 184a. As seen in FIG. 3, this first inflation/deflation protocol lowers the left side of the cushion 180 and raises the right side thereof thereby providing a “trough,” illustrated at 192, on the left side to prevent the patient 171 from falling off the mattress. The patient 171 is thus “caught” by the upper crib 178 with the fabric strip 190 providing lateral stability to prevent the crib 178 from bowing outwardly.
FIG. 4 illustrates tilting of the cushion 180 from the position of FIG. 2 to about a 15 degree angle to the other side by deflating the right side upper bladder 182a and by inflating the left side lower bladder 184b. This second inflation/deflation protocol lowers the right side of the cushion 180 and raises the left side thereof thereby providing a “trough” 192 on the right side to prevent the patient from falling off the mattress. The fabric strip 190 again provides lateral stability to prevent the crib from bowing outwardly.
The cushion 180 may of course be tilted to a higher angle than 15 degrees. For example, the cushion 180 may be tilted to an angle of perhaps about 45 degrees by further inflation of the corresponding lower bladder 184, allowing ballooning thereof so that it approaches a tubular shape, and the width of the fabric strip 190 is selected to suitably accommodate the degree of tilt.
Conventional Rotating Mattress' Fulcrum Point
As identified above, rotating mattresses are some times made with a crib. The crib is designed to inhibit a patient from falling off the mattress by having the patient caught within the trough between the cushion material and the crib. There is at least one problem with catching the patient in a trough.
That problem is the patient can get too close to the crib while in the trough which can cause adverse effects. An example of an adverse effect includes and is not limited to a patient being trapped between the cushion and the crib and/or the crib increasing the tissue interface pressure to the patient's skin. That event can occur because a rotating mattress' fulcrum 700 is at the cushion's edge closest to the trough. The mattress' fulcrum at the cushion's edge is undesirable because it promotes a patient to (a) fall off the mattress when a crib is not used and/or (b) be positioned against the crib when a crib is used which can increase the patient's tissue interface pressure. The present invention is designed to solve that problem(s).